1 #include<iostream>
2
3 using namespace std;
4
5 typedef int QueueElement;
6
7 struct Node
8
9 {
10
11 Node *next;
12
13 QueueElement data;
14
15 Node(QueueElement value, Node *link = NULL) :data(value), next(link){}
16
17 };
18
19 class Queue
20
21 {
22
23 public:
24
25 Queue() :myFront(NULL),myBack(NULL) {}
26
27 ~Queue()
28
29 {
30
31 Nodeptr ptr = myFront, nextptr;
32
33 while (ptr != 0)
34
35 {
36
37 nextptr = ptr->next;
38
39 delete ptr;
40
41 ptr = nextptr;
42
43 }
44
45 }
46
47
48
49 Queue(const Queue& original)
50
51 {
52
53 myFront = myBack = 0;
54
55 if (!original.empty())
56
57 {
58
59 myFront=myBack= new Node(original.Front());
60
61 Nodeptr origPtr = original.myFront->next;
62
63 while (origPtr != 0)
64
65 {
66
67 myBack->next = new Node(origPtr->data);
68
69 myBack = myBack->next;
70
71 origPtr = origPtr->next;
72
73 }
74
75 }
76
77 }
78
79
80
81 Queue& operator=(const Queue& rhs)
82
83 {
84
85 if (this != &rhs)
86
87 {
88
89 this->~Queue();
90
91 if (rhs.empty())
92
93 myFront = myBack = 0;
94
95 else
96
97 {
98
99 myFront = myBack = new Node(rhs.Front());
100
101 Nodeptr rhsPtr = rhs.myFront->next;
102
103 while (rhsPtr != 0)
104
105 {
106
107 myBack->next = new Node(rhsPtr->data);
108
109 myBack = myBack->next;
110
111 rhsPtr = rhsPtr->next;
112
113 }
114
115 }
116
117 }
118
119 return *this;
120
121 }
122
123
124
125 QueueElement Front() const
126
127 {
128
129 if (!empty())
130
131 {
132
133 return (myFront->data);
134
135 }
136
137 else
138
139 {
140
141 cout << "The Stack is empty!" << endl;
142
143 }
144
145 }
146
147
148
149 bool empty() const
150
151 {
152
153 return myFront == 0;
154
155 }
156
157 void enqueue(const QueueElement& value)
158
159 {
160
161 Nodeptr newptr= new Node(value);
162
163 if (empty())
164
165 {
166
167 myFront = myBack = newptr;
168
169 }
170
171 else
172
173 {
174
175 myBack->next = newptr;
176
177 myBack = newptr;
178
179 }
180
181 }
182
183
184
185 void Display()
186
187 {
188
189 Nodeptr ptr;
190
191 for (ptr = myFront; ptr != 0; ptr = ptr->next)
192
193 cout << ptr->data << " ";
194
195 cout << endl;
196
197 }
198
199 void dequeue()
200
201 {
202
203 if (!empty())
204
205 {
206
207 Nodeptr ptr = myFront;
208
209 myFront = myFront->next;
210
211 delete ptr;
212
213 if (myFront == 0)
214
215 myBack == 0;
216
217 }
218
219 else
220
221 {
222
223 cout << "Stack is empty" << endl;
224
225 }
226
227 }
228
229 private:
230
231 typedef Node* Nodeptr;
232
233 Nodeptr myFront;
234
235 Nodeptr myBack;
236
237 };
238
239 void main()
240
241 {
242
243 Queue s;
244
245 cout<<s.empty()<<endl;
246
247 for (QueueElement i = 1; i < 6; ++i)
248
249 {
250
251 s.enqueue(i);
252
253 }
254
255 cout << s.empty() << endl;
256
257 cout << s.Front() << endl;
258
259 s.Display();
260
261 s.dequeue();
262
263
264
265 s.Display();
266
267 Queue s1;
268
269 s1 = s;
270
271 s.Display();
272
273 Queue s2(s);
274
275 s2.Display();
276
277 system("pause");
278
279 }
